Physics professor: Some scientists claim

Answer choices

1. A

   Out of Scope11% picked this

   Superheated plasma in which electrical resistance fails does not cause types of lightning other

   Out of Scope: other than ball lightning This argument is only about ball lightning.

   11%
2. B

   Too Weak2% picked this

   The phenomena observed by the physics professor were each observed by at least

   This strengthens the argument somewhat, to know that the professor's accounts can be corroborated by other people. But that doesn't "seal the deal" and guarantee the incredibly strong wording of the conclusion that "X is never a factor in causing ball lightning."

   2%
3. C

   Weakens10% picked this

   Ball lightning can occur as the result of several

   If ball lightning has lots of different origins stories, then there's no reason to think that the instances the physics professor observed show the full range of possibility. The author is boldly saying X is never a factor, so she's really trusting that what she saw speaks for all cases. This answer makes it sound like different cases of ball lightning could be unfair to compare.

   10%
4. D

   Unrelated to Goal11% picked this

   Superheating of gaslike substances causes bright light to

   This is pulling together language from within the premises so that we see some sort of Linking answer and consider it. The argument said that superheating plasma (a gaslike substance), were it to spark some ball lightning, would cause that ball lightning to emit intense light. We already knew superheating gaslike substances can lead to bright light being emitted, so this answer is only pumping up the strength of what we already knew. But it has nothing to do with helping us know for sure that "if X wasn't a factor in the instances the professor observed, then X is never a factor in ball lightning." All this answer would be doing is adding more corroboration for the professor's story that the instances of ball lightning she observed are enough for us to say something would never be true about ball lightning.

   11%
5. E

   Correct65% picked this

   All types of ball lightning have the

   Why this is right

   We know that when superheated plasma with failed electrical resistance (X) causes ball lightning, there would be intense light and rising in the air. The instances the professor observed were not-bright light and not-rising in the air. So we know that X was not a factor in those instances of ball lightning. This answer allows us to generalize from those instances to all instances, by giving us a powerful idea that every case of ball lightning has the same causal factor. Thus, if X wasn't a causal factor in the instances the professor observed, then X is never a causal factor.

   Skill tested: Sufficient Assumption · how this choice captures the argument's function is the move to repeat next time.

   65%